African sugar cane borer

The usefulness of the organoaluminum-mediated pinacol-type rearrangement is demonstrated in the synthesis of (+ )-eldanolide (354), a wing-gland pheromone of the African sugar-cane borer [112] (Scheme 48). The key reaction, the rearrangement of 350 351,... 

Butenolide 1012 is a key intermediate in the synthesis of ( + )-eldanolide (1013), a pheromone of the African sugar-cane borer Eldana saccharina. It is synthesized in 5 steps and 48% overall yield from (7 )-malic acid v/a (7 )-l,2,4-butanetriol (984) (Scheme 150) [218]. 

Scheme8.18 Synthesis of African sugar cane borer pheromone. Conditions for LiCHCh reactions and chloride substitutions as described in Schemes 8.1 and 8.3.

Butyrolactones.—y-Epoxyesters have been used as effective precursors of butyrolactones in one case sodium benzenethiolate brings about epoxide opening and lactonization occurs in a separate step. Similarly, attack of a vinyl cuprate on the epoxyester (78) leads directly to a mixture of lactones from which the rran5-lactone (79) is isolated the latter compound is the wing gland pheromone of the male african sugar-cane borer (Scheme 61). ... 

The absolute configuration of eldanolide, the pheromone from the wing glands of the male African sugar-cane borer, has been determined by a chiral synthesis of both of its enantiomers. (-t-)-Pantolactone (141) has been synthesized (in 40% yield) by a short sequence from (—)-(5 )-dimethyl malate. 1,2-0-Isopropyl-idene-D-glyceraldehyde is a useful chiral starting material for the synthesis of butyrolactones such as (142). The keto-lactone (143) is a useful intermediate in the synthesis of (+)-D-pantothenic acid it is prepared from readily available starting materials. ... 

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