- Total synthesis of selaginpulvilins A and C
-
An efficient formal total synthesis of two compounds from the selaginpulvilin family of natural products, selaginpulvilin A and C, has been successfully achieved. The tetradehydro Diels-Alder (TDDA) reaction between an enyne and alkyne has been utilized for the creation of the necessary fluorene skeleton. Attempts at the conversion of selaginpulvilin A to selaginpulvilin B, F and H were unsuccessful.
- Chinta, Bhavani Shankar,Baire, Beeraiah
-
p. 262 - 265
(2018/01/12)
-
- Some special features of hydroalumination-iodination of alkyne-1,4-diols
-
Hydroalumination-iodination of alkyne-1,4-diols of different structure showed that with increasing number of substituents at the C-OH group the amount of β-iodo-substituted products with respect to this group increased. In the case of symmetric secondary 1,4-diols the reaction results in a 1: 1 mixture of stereoisomeric iodoalkenediols, and in the case of phenyl substituents the reaction proceeds regio- and stereoselectively to give an alkenediol iodine atom in the β-position to phenyl group.
- Gharibyan,Makaryan,Hovhannisyan,Kinoyan,Chobanyan
-
p. 457 - 464
(2014/05/20)
-
- Studies on the Cu(I)-catalyzed regioselective anti-carbometallation of secondary terminal propargylic alcohols
-
A highly regioselective Cu(I)-catalyzed anti-carbometallation of secondary terminal propargylic alcohols with 1° alkyl or aryl Grignard reagents affording 2-substituted allylic alcohols was developed. By using this method, optically active allylic alcohols can be prepared from the optically active propargylic alcohols without obvious loss of the enantiopurity. The cyclic organometallic intermediate formed may undergo an iodination or a Pd(0)-catalyzed coupling reaction to afford stereo-defined allylic alcohols.
- Lu, Zhan,Ma, Shengming
-
p. 2655 - 2660
(2007/10/03)
-
- Substituted bicyclic derivatives useful as anticancer agents
-
The invention relates to compounds of the formula 1 and to pharmaceutically acceptable salts and solvates thereof, wherein A, X, R1, R3and R4are as defined herein. The invention also relates to methods of treating abnormal cell growth in mammals with administering the compounds of formula 1 and to pharmaceutical compositions for treating such disorders which contain the compounds of formula 1. The invention also relates to methods of preparing the compounds of formula 1.
- -
-
-
- Enantioselective synthesis of both enantiomers of various propargylic alcohols by use of two oxidoreductases
-
The oxidoreductases Lactobacillus brevis alcohol dehydrogenase (LBADH) and Candida parapsilosis carbonyl reductase (CPCR) are suitable catalysts for the reduction of ketones to afford enantiopure sec. alcohols. A broad variety of alkynones (1, 3, and 5) are accepted as substrates and the corresponding propargylic alcohols (2, 4, and 6) are obtained in good yield and excellent enantiomeric excess. By changing the steric demand of the substituents the ee values can be adjusted and even the configurations of the products can be altered.
- Schubert, Thomas,Hummel, Werner,Kula, Maria-Regina,Mueller, Michael
-
p. 4181 - 4187
(2007/10/03)
-
- Synthesis and cytotoxic activity of a series of diacetylenic compounds related to falcarindiol
-
The synthesis of a series of diacetylenic compounds related to the natural product falcarindiol has been carried out. Unsymmetrical diacetylenes were prepared by a modification of the Cadiot-Chodkiewicz coupling reaction, while a Glaser coupling was used to prepare symmetrical diacetylenes. These compounds have been tested for in vitro cytotoxic activity against Hep-G2, and H-4-II-E cell lines. Diacetylenes with additional unsaturation at C-1, 2, appended with hydroxyl groups at C-3 and C-8, or with long hydrophobic chains, exhibited IC50 values in the micromolar range.
- Setzer,Gu,Wells,Setzer,Moriarity
-
p. 1776 - 1777
(2007/10/03)
-
- Facile preparation of substituted allenic esters via the ortho ester Claisen rearrangement
-
Five substituted allenic esters were prepared in good yields through the ortho ester Claisen rearrangement of primary and secondary propargyl alcohols.
- Lai,Anderson
-
p. 4087 - 4091
(2007/10/03)
-
- Synthetic studies towards spirostaphylotrichins: Synthesis of building blocks
-
A retrosynthetic strategy for the total synthesis of spirostaphylotrichins is presented. The building blocks 7, 8 and 16 were synthesized.
- Steiner,Tamm
-
p. 6729 - 6732
(2007/10/02)
-
- HYDRATION TRIMERIZATION OF ACETYLENE IN SUPERBASIC MEDIA III. VINYLATION OF ACETYLENIC ALCOHOLS AS INTERMEDIATE STAGE
-
It was confirmed that the hydration-trimerization of acetylene to 2-vinyloxy-1,3-butadiene in superbasic media takes place by a stepwise mechanism, involving the initial formation of acetaldehyde, its ethynylation, vinylation of the acetylenic alcohol, and prototropic acetyl-allene-1,3-diene rearrangements.A method was developed for the direct vinylation of primary and secondary acetylenic alcohols in the potassium hydroxide-DMSO system, leading to 3-vinyloxy-1-alkynes and 3-vinyloxy-1,2-alkadienes with overall yields of 45-87percent .
- Tarasova, O. A.,Trofimov, B. A.,Afonin, A. V.,Sinegovskaya, L. M.,Kalinina, N. A.,Amosova, S. V.
-
p. 1018 - 1025
(2007/10/02)
-
- ASYMMETRIC SYNTHESIS BASED ON CHIRAL DIAMINES HAVING PYRROLIDINE RING
-
Various highly stereoselective asymmetric reactions based on chiral diamines having pyrrolidine ring are described.Some of these reactions have been successfully applied to the syntheses of natural products.
- Mukaiyama, Teruaki
-
p. 4111 - 4119
(2007/10/02)
-
