Eggen, MariJean published the artcileTotal Synthesis of Cryptophycin-24 (Arenastatin A) Amenable to Structural Modifications in the C16 Side Chain, Formula: C21H37BO, the publication is Journal of Organic Chemistry (2000), 65(23), 7792-7799, database is CAplus and MEDLINE.
Two efficient protocols for the synthesis of tert-Bu (5S,6R,2E,7E)-5-[(tert-butyldimethylsilyl)oxy]-6-methyl-8-phenyl-2,7-octadienoate, a major component of the cryptophycins, are reported. The first utilized the Noyori reduction and Frater alkylation of Me 5-benzyloxy-3-oxopentanoate to set two stereogenic centers, which became the C16 hydroxyl and C1′ Me of the cryptophycins. The second approach started from 3-p-methoxybenzyloxypropanal and a crotyl borane reagent derived from (-)-α-pinene to set both stereocenters in a single step and provided the dephenyl analog, tert-Bu (5S,6R,2E)-5-[(tert-butyldimethylsilyl)oxy]-6-methyl-2,7-octadienoate, in five steps. This compound was readily converted to the 8-Ph compound via Heck coupling. The silanyloxy esters were efficiently deprotected and coupled to the C2-C10 amino acid fragment to provide desepoxyarenastatin A and its dephenyl analog. The terminal olefin of the latter was further elaborated via Heck coupling. Epoxidation provided cryptophycin-24 (arenastatin A).
Journal of Organic Chemistry published new progress about 99438-28-5. 99438-28-5 belongs to ethers-buliding-blocks, auxiliary class Chiral,Aliphatic cyclic hydrocarbon, name is (+)-B-Methoxydiisopinocampheylborane, and the molecular formula is C21H37BO, Formula: C21H37BO.
Referemce:
https://en.wikipedia.org/wiki/Ether,
Ether | (C2H5)2O – PubChem