5- Hydroxyhept-6-enoates

Hydroxyhept-6-enoates have been key intermediates in the synthesis of a variety of natural products, especially of the arachidonic acid metabolic pathway, including prostaglandins, leukotrienes, and isoprostanes [105, 113-118]. The usage of two enantiocomplementary enzymes allowed convenient access to both enantiomers via an ADH-catalyzed reduction of 5-oxo-hept-6-enoate. Alcohol dehydrogenase from Lactobacillus brevis (ADH-LB) furnished the (S )-enantiomer, Thermoanaerobacter sp. ADH (ADH-T) the (7 )-enantiomer in excellent enantiomeric access respectively [119]. A cross-metathesis reaction followed by cyclopropanation led to the formal synthesis of constanolactones C and D (Fig. 16) [86, 120, 121]. 

Fischer and Pietruszka have reported the efficient synthesis of both enantiomers of ethyl 5-hydroxyhept-6-enoate (3, Scheme 4.3) using isolated alcohol dehydrogenases (ADHs) and 2-propanol as cofactor recycling system in a coupled-substrate approach [33]. 6-Hydroxy esters have been used as key intermediates for a variety... 

Scheme4.3 Synthesis of enantiopure ethyl 5-hydroxyhept-6-enoate (3) employing isolated ADHs.

Fischer, T. and Pietruszka, J. (2007) Efficient synthesis of either enantiomer of ethyl 5-hydroxyhept-6-enoate. Adv. Synth. Catal., 349 (8-9), 1533-1536. 

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