88154-76-1

Upstream product

• 115464-52-3 endo-2-butyl-1-methoxy-endo-3-methylbicyclo<3.2.2>non-6-en-exo-2-ol 
• 115464-53-4 4-butyl-exo-3-methylbicyclo<4.3.0>non-4-en-endo-7-ol 
• 103931-11-9 1-methoxy-endo-3-methylbicyclo<3.2.2>non-6-en-2-one 
• 103931-14-2 tert-Butyl-((1S,3aS,5S,7aS)-6-butyl-5-methyl-2,3,3a,4,5,7a-hexahydro-1H-inden-1-yloxy)-dimethyl-silane 
• 115464-54-5 (3S,3aS,6S,7aS)-5-Butyl-3-(tert-butyl-dimethyl-silanyloxy)-6-methyl-octahydro-inden-4-ol 
• 103931-13-1 4-butyl-exo-3-methylbicyclo<4.3.0>non-4-en-7-one 
• 103931-12-0 1-butyl-exo-8-methylbicyclo<3.2.2>non-6-en-2-one 
• 53922-08-0 1-methoxybicyclo<3.2.2>non-6-en-2-one 
• 88525-26-2 endo-3-butyl-exo-4-methylbicyclo<4.3.0>non-1(9)-en-2-one 
• 113-00-8 guanidine nitrate 
• 86509-61-7 (6SR,7aSR)-5-butyl-6-methyl-1,2,5,6,7,7a-hexahydroinden-4-one 
• 115464-55-6 3-butyl-exo-4-methyl-endo-9-(tert-butyldimethylsiloxy)bicyclo<4.3.0>nonan-2-one 

Relevant academic research and scientific papers

Rearrangement Approaches to Cyclic Skeletons. 6. Total Synthesis of (+/-)-Ptilocaulin on the Basis of Formal Bridgehead Substitution and Photochemical Acyl Migration of a Bicyclonon-6-en-2-one System

The total synthesis of (+/-)-ptilocaulin (1), the antimicrobial and cytotoxic guanidine-containing natural product, starting from 1-methoxybicyclonon-6-en-2-one (3) is reported.The 3-endo-methyl derivative of 3, 4, was obtained selectively under kinetically controlled conditions.The bridgehead methoxy group of 4 was replaced by a butyl group, with inversion of absolute configurations, upon successive treatment with butyllithium and p-toluenesulfonic acid in benzene.The thus obtained 1-butyl-exo-8-methylbicyclonon-6-en-2-one was transformedpchotochemically into the fused-ring ketone, 4-butyl-exo-3-methylbicyclonon-4-en-7-one (7).Transposition of the carbonyl group and the olefin of 7 to give a mixture of exo-3- and endo-3-butyl-4-exo-methylbicyclonon-9-en-2-ones was achieved in a six-step seqence.From these conjugated ketons, (+/-)-ptilocaulin was derived by treatment with guanidine.

A stereocontrolled synthesis of (±)-ptilocaulin via a Rh(I)-catalyzed intramolecular [4+2] cycloaddition

A stereospecific Rh(I)-catalyzed intramolecular [4+2] cycloaddition has been used to elaborate the essential carbocyclic core of (±)-ptilocaulin. Georg Thieme Verlag Stuttgart - New York.

Stereoselective Total Synthesis of (+/-)-Ptilocaulin and its 7-Epimer. A Strategy Based On the Use of an Intramolecular Nitrile Oxide Olefin Cycloaddition (INOC) Reaction

A stereoselective total synthesis of (+/-)-ptilocaulin 1, an antimicrobial anticancer agent as well as of its 7-epimer 23 is described.The strategy involves an aldol condensation of the dithio dianion of the Z-aldoxime (13) with a ketone 6 to produce 11 and the stereospecific intramolecular cycloaddition of the nitrile oxide 5, generated in situ from 11.The resulting isoxazoline 4 was converted to hydroxy ketone 3 which serves as a starting point for introduction of the fourth stereocenter at C-7.Lithium in ethylamine reduction of 3 produces stereospecifically the 7β-methyl compound which leads to ptilocaulin 1, while catalytic hydrogenation of 3 introduces the 7α-methyl substituent and finally 7-epiptilocaulin 23.H- and C NMR analysis permits differentation between isomers of intermediates.When, in the last step of the synthesis of 1 or 23 from 19 or 22 and guanidine, a higher temperature (>130 deg C) was applied, an interesting disproportionation to aminopyrimidine 25 or 28 and cyclic guanidine 24 or 27 was observed.