C40 archaebacterial diol

Reaction of reagent (27) with crotonaldehyde provides a syn aldol, which is transfoimed by a four-step sequence including a Claisen rearrangement into (35 equation 55). Aldol (36), obtained from (27) and acrolein, was converted via propionate (37) into (38), a building block for the vitamin E side chain (equation 56). The strategy of parlaying the 1,2 relative stereochemistry obtainable from the aldol reaction into 1,5 relative stereochemistry by use of a Claisen rearrangement has also been used to prepare the C40 archaebacterial diol and one of its stereoisomers. ... 

Heathcock, C.H., Finkelstein, B.L., Jarvi, E.T., Radel, PA. and Hadley, C.R. (1988). 1,4-and 1,5-Stereoselection by sequential Aldol addition to a,6-unstaurated aldehydes followed by Claisen rearrangement. Application to total synthesis of the vitamin E side chain and the archaebacterial C40 diol. J. Org. Chem., 53,1922-1942. 

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