Synthesis 2011(10): 1626-1632  
DOI: 10.1055/s-0030-1260014
PAPER
© Georg Thieme Verlag Stuttgart ˙ New York

A Novel Asymmetric Synthesis of the Core Octadienoic Acid Unit of Cryptophycins from (R)-2,3-O-Cyclohexylideneglyceraldehyde

Dibakar Goswami, Payel Sur, Angshuman Chattopadhyay, Anubha Sharma, Subrata Chattopadhyay*
Bio-Organic Division, Bhabha Atomic Research Centre, Mumbai 400 085, India
Fax: +91(22)25505151; e-Mail: schatt@barc.gov.in;
Further Information

Publication History

Received 4 February 2011
Publication Date:
20 April 2011 (online)

Abstract

A facile asymmetric synthesis of the octadienoic acid unit of cryptophycins was developed starting from (R)-2,3-O-cyclohexylideneglyceraldehyde. The key steps of the synthesis are the stereocontrolled generation of the required asymmetric centers through (i) a gallium-mediated highly diastereoselective crotylation of the glyceraldehyde in [bmim][Br], (ii) a stereoselective allylation with allyltributylstannane, and (iii) an enantioselective Grignard addition to an α-oxygenated aldehyde.