1\5!Dimethoxy cinnamaldehyde in T[ ~oridana and structural revision of taxi~orine
0252
Although 00 is listed in the Chemical Abstracts with "ponasterone A 8 "9[995)# ð01Ł and "4Ð09) meth!
an accession number\ and cited in two references ð05\ anol#\ 09!deacetyl paclitaxel!6!xyloside 5 "9[992)# ð7Ł[
06Ł\ a close examination of these two references failed
The initial dichloromethane eluate "9[14 g# was
to show this compound[ Since neither its isolation nor applied to another silica column "2 g# using 14) ethyl
its synthesis has been described so far\ 00 is a novel acetate:ligroin[ This gave the trans 1\5!dimethoxy cin!
natural product[ Furthermore\ no other 1\5!oxy! namaldehyde 00 "9[991)#[ Elution continued with
genated "hydroxy\ methoxy\ or hydroxy!methoxy# 49) ethyl acetate:ligroin\ which gave a!conidendrin
cinnamyl or cinnamoyl entities have been isolated\ 09 "9[994)# ð03Ł\ followed by 0!deoxy baccatin IV 3
either as the alcohol\ the acid or the ester[ Only 1\5! "9[992)# ð5Ł[
dimethoxy cinnamic acid ð07Ð10Ł and its methyl and
Taxchinin M "Taxi~orine# M 0b[ This was obtained
ethyl esters ð11Ł are known as synthetic products[ Thus as a crystalline solid "acetone:ligroin#\ m[p[ 143Ð
00 represents the _rst such example of a naturally 144>C\ ðaŁD\−15[0>[
occurring 1\5!oxygenated cinnamoyl moiety[ In
Acetyl taxi~orine 1[ Acetylation of 0b with acetic
general\ the most common naturally occurring exam! anhydride:pyridine gave 1 as a glassy solid ð0Ł[ The
ples of 0]2!dioxy benzenoid compounds contain a HMBC spectrum is shown in Table 0[
carbon substituent at the 3!position "e[g[ resa!
Oxidation of 0b to 2[ To 0b "9[0 g# in acetone "1 ml#
cetophenone\ umbelliferone# or at the 4!position "e[g[ was added Jones reagent[ After 29 min\ water was
orcinol\ resveratrol#[ The biogenetically most favored added and the product recovered by extraction with
cinnamic acids\ contain the 2\3!dioxy substitution dichloromethane[ It was crystallized from ether:
"e[g[ ca}eic acid#[
ligroin\ m[p[ 190Ð193>C\ yield\ 9[944 g^ uv\ lmax\ 121
and 142^ ir "KBr pellet#\ 2419\ 1879!1819\ 0649!0619\
0329\ 0254\ 0124\ 0919 and 694 cm−0[ Anal[ Calc[ for
C24H31O02] C\ 51[57^ H\ 5[20[ Fd[ C\ 51[26^ H\ 5[47[
02!Deacetyl taxi~orine "taxchinin L# 6[ This was
EXPERIMENTAL
0H and 02C NMR\ COSY and the HETCOR spec!
tra] Varian VXR!299 and Varian Gemini!299 spec! obtained as a crystalline solid from ether:ligroin\ yield\
trometers[ FAB mass spectra] Finnigan Mat 849 Q 9[07 g\ 9[90)\ m[p[ 137Ð149>C[ The spectral data
spectrometer[ IR spectra] Perkin!Elmer 0319 ratio rec! agreed with those given for taxchinin L ð4Ł[
ording spectrophotometer[ UV spectra] Perkin!Elmer
Trans 1\5!dimethoxy cinnamaldehyde "00#[ Con!
Lambda 2B spectrophotometer[ Mps "uncorr#] Fisher centration of the appropriate fractions gave 00 as a
apparatus[ TLC] silica gel\ 59 HF143 "E[ Merck and glass\ yield\ 9[91 g^ lmax 202 nm^ IR "KBr#] 2099\ 1839!
Aldrich# with MeOHÐMe1COÐCH1Cl1 "0]3]04# or 2999\ 1709\ 1639!1699\ 0559\ 0594!0474\ 0364\ 0159\
0
EtOAc:Ligroin "1]4# as solvents\ visualization by UV 0039\ 0099!0979\ 869\ 739\ 614 cm−0[\ H NMR\ d
"143 nm# and charring with dilute H1SO3 spray[ Col! 2[89\ s\ 5H\ "OMe#^ 5[47\ d\ J ꢁ 7[3 Hz\ 1H\ "Ar!2\
umn chromatography] Silica gel\ 099Ð199 mesh "Ald! 4H#\ 6[06\ dd\ J ꢁ 6[7\ 05[9 Hz\ 0H\ "H!0#^ 6[22\ t\
rich#[
J ꢁ 7[3 Hz\ 1H\ "Ar!3H#^ 6[82\ d\ J ꢁ 05[9 Hz\ 0H\
"H!2#^ 8[53\ d\ J ꢁ 7[0 Hz\ 1H\ "H!0#[ 02C NMR\ d
44[7×1\ "OMe#^ 092[5\ "Ar!2\ 4#^ 001[0 "Ar!0#^ 020[5\
"C!1#^ 021[5\ "Ar!3#^ 033[4\ "C!2#^ 059[4\ "Ar!1\5#^
Fractionation of the extract of T[ ~oridana
Fresh needles and small twigs of T[ ~oridana\ col! 085[3\ "C!0#^ MS\ 081 "29)#\ 050 "099)#\ 038 "06)#\
lected from the campus of the University of Florida\ 80 "04)#[ The IR and NMR spectral data agreed with
"1 kg# were extracted and processed by reversed phase those for the synthetic aldehyde prepared as shown
column chromatography using C!07 bonded silica and below[
acetonitrile:water as described earlier ð0Ł[ Those frac!
Trans 1\5!Dimethoxy cinnamic acid 01[ This was
tions from the 14Ð39) acetonitrile:water were freed prepared by heating 1\5!dimethoxy benzaldehyde "0[1
from 09!deacetyl baccatin III and concentrated to a g\ Aldrich#\ malonic acid "0[3 g\ 1 eq[# in pyridine "03
syrupy solid "09 g#[
ml# and piperidine "9[1 ml# under re~ux for 19 h[ The
On standing\ this became a crystalline semi!solid product was crystallized from ether:ligroin\ yield 0[73
"mostly rhododendrol 7#\ and 2 g of this was chro! g "73)#\ m[p[ 033Ð035>C\ "lit[ "07# 030Ð032>C#[
matographed on a normal phase silica column "39 g# in
Methyl trans 1\5!dimethoxy cinnamate 02[ Com!
dichloromethane[ The column was eluted successively pound 01 "0[14 g# was methylated in acetone with
with dichloromethane containing 1\ 4 and 09) dimethyl sulfate "9[6 ml# and potassium carbonate "1
acetone\ and then with the addition of 1\ 4 and 09) g#[ The solid was crystallized from ether:ligroin\ to
methanol[
give the ester\ yield\ 0[14 g "81)#\ m[p[ 75Ð77>C[
The following compounds were obtained in
Trans 1\5!Dimethoxy cinnamyl alcohol 03[ Com!
succession\ with the yields being calculated from the pound 02 "0[14 g# in THF"19 ml# was reduced with
fresh needles] "1) acetone#\ 0!b!hydroxy baccatin 0 4 lithium aluminum hydride "9[4 g#[ The product 03\ a
"9[90)# ð6Ł\ and taxchinin M "previously taxi~orine# colorless liquid "9[6 g\ 53)#\ was directly used for the
0b "9[995)# ð0Ł^ "4) acetone#\ rhododendrol 7\ next step[
"9[94)# ð09Ł and taxchinin L 6 "9[90)# ð4Ł\ "09)
Trans 1\5!Dimethoxy cinnamaldehyde 00[ Oxi!
acetone# 09!deacetyl baccatin III\ "1) methanol#\ dation of 03 "9[6 g# with chromic anhydride "3 g#