251641-22-2

Upstream product

• 251641-19-7 (2S,6S,8S)-2,8-Bis-(2-benzyloxy-ethyl)-10-triisopropylsilanyloxy-1,7-dioxa-spiro[5.5]undec-10-en-4-one 
• 251641-21-1 (2S,4S,6R,8S)-2,8-Bis-(2-benzyloxy-ethyl)-10-triisopropylsilanyloxy-1,7-dioxa-spiro[5.5]undec-10-en-4-ol 

Downstream Products

• 185409-89-6 (2S,4S,6R,8S,10S)-2,8-Bis-(2-benzyloxy-ethyl)-10-(tert-butyl-dimethyl-silanyloxy)-4-methyl-1,7-dioxa-spiro[5.5]undecan-4-ol 
• 251641-31-3 [(2R,4S,6S,8S,10S)-8-[(2S,3R)-4-((R)-4-Benzyl-2-oxo-oxazolidin-3-yl)-2-hydroxy-3-methyl-4-oxo-butyl]-4-(tert-butyl-dimethyl-silanyloxy)-10-hydroxy-10-methyl-1,7-dioxa-spiro[5.5]undec-2-yl]-acetic acid tert-butyl ester 

Relevant academic research and scientific papers

Synthesis of the C1-C28 Portion of Spongistatin 1 (Altohyrtin A)

A synthetic approach was developed to the C1-C28 subunit of spongistatin 1 (altohyrtin A, 65). The key step was the coupling of the AB and CD spiroketal moieties via an anti-aldol reaction of aldehyde 62 and ethyl ketone 57. The development of a method for the construction of the AB spiroketal fragment is described and included the desymmetrization of C2-symmetric diketone 10 and the differentiation of the two primary alcohols of 16. Further elaboration of this advanced intermediate to the desired aldehyde 62 included an Evans' syn-aldol reaction and Tebbe olefination. The synthesis of the CD spiroketal fragment 56 involved the ketalization of a triol-dione, generated in situ by deprotection of 45, to provide a favorable ratio (6-7:1) of spiroketal isomers 46 and 47, respectively. The overall protecting group strategy, involving many selective manipulations of silyl protecting groups, was successfully developed to provide the desired C1-C28 subunit of spongistatin 1 (altohyrtin A) (65).