Synthesis of [7,7‐²H₂]epibrassinolide

Abstract

Synthesis of labelled epibrassinolide containing two deuterium atoms in a position which is not subjected to isotopic exchange is reported. Key transformations include preparation of 6,7-seco steroidal diacid, its cyclization to a cyclic anhydride followed by a regioselective reduction with NaBD 4 . The obtained [7, H 2 ]epibrassinolide can be used in biochemical experiments when the loss of isotopic label should be avoided.

Steroid plant hormones: Effects outside plant kingdom

“…The pharmacokinetics of EBl was studied in rats by intragastric administration of its 3 H-labelled form [82]. It was well absorbed from the gastrointestinal tract following the administration and quickly distributed to blood, liver, intestines, lungs and kidneys.…”

Synthetic Aspects of Brassinosteroids

“…of 2,2-dimethoxypropane proceeded with the formation of monoacetonides (58) and (59) (Scheme 6.8) [32]. of 2,2-dimethoxypropane proceeded with the formation of monoacetonides (58) and (59) (Scheme 6.8) [32].…”

“…An attempt to solve this problem was made by Khripach et al [58] in the synthesis of [7,7-2 H 2 ]24-epibrassinolide (138) (Scheme 6.26). Opening of the lactone ring in epibrassinolide diacetonide (132) by strong alkali followed by Dess-Martin periodinane oxidation of the intermediate alcohol (133) produced the aldehyde (134).…”

Labelling of brassinosteroids by isotopes of hydrogen and carbon

“…Acidic hydrolysis of acetonide groups on 155 provided [7,7-2 H 2 ]epiBL 156 with 82% isotopic enrichment. 51…”