187102-96-1Relevant articles and documents
A flexible approach to azasugars: asymmetric total syntheses of (+)-castanospermine, (+)-7-deoxy-6-epi-castanospermine, and (+)-1-epi- castanospermine
Liu, Gang,Wu, Tian-Jun,Ruan, Yuan-Ping,Huang, Pei-Qiang
supporting information; experimental part, p. 5755 - 5768 (2010/08/19)
The asymmetric total synthesis of natural azasugars (+)-castanospermine, (+)-7-deoxy-6-epI-castanospermine, and synthetic (+)-1-epi-castanospermine has been accomplished in nine to ten steps from a common chiral building block (S)-8. The method features a powerful chiral relay strategy consisting of a highly diastereoselective vinylogous Mukaiyama-type reaction with either chiral or achiral aldehydes (≥ 95% de; de = diastereomeric excess) and a diastereodivergent reduction of tetramic acids, which allows formation of three continuous stereogenic centers with high diastereo-selectivities. The method also provides a flexible access to structural arrays of 5-(α-hydroxyalkyl) tetramic acids, such as 17/34, and 5-(α-hydroxyalkyl)-4-hydroxyl-2- pyrrolidinones, such as 18 and 25/35 a. The method constitutes the first realization of the challenging chiral synthons A and D and thus of the conceptually attractive retrosynthetic analysis shown in Scheme 1 in a highly enantioselective manner.
Stereoselection in radical cyclization of β-alkoxyvinyl sulfoxides: Synthesis of tetrahydrofuranyl allyl carbinols
Keum, Gyochang,Kang, Soon Bang,Kim, Youseung,Lee, Eun
, p. 1895 - 1897 (2007/10/03)
Equation presented. Tetrahydrofuranyl allyl carbinols may be prepared stereoselectively via radical cyclization of β-alkoxyvinyl sulfoxides, Pummerer rearrangement, and reaction with allylstannane.
An enantiocontrolled synthesis of pyrrolizidines, (-)-platynecine and (-)-hadinecine
Kang, Sung Ho,Kim, Geun Tae,Yoo, Yong Sang
, p. 603 - 606 (2007/10/03)
Trisubstituted allylic alcohols 13 and 14 have been converted into a single isomeric trans-oxazoline 16 via an intramolecular iodoamidation of the corresponding trichloroacetimidates, which have been elaborated into (-)-platynecine 1 and(-)-hadinecine 2 via a common intermediate pyrrolizidine.