Commonly used approaches for the construction of iminoquinones include (i) metal catalysis [5-7], (ii) photosynthesis by UV lamps and photosensitizers , (iii) 2-iodoxybenzoic acid [IBX, 1-hydroxy-1,2-benziodoxol-3(1H)-one 1-oxide] oxidation [8,9], and (iv) Dess-Martin periodinane
[DMP, 1,1,1-triacetoxy1,1-dihydro-1,2-benziodoxol-3(1H)-one]-mediated oxidative reaction .
Ohkubo, Dess-Martin Periodinane
Oxidation of Alcohols in the Presence of Stabilized Phosphorus Ylides:A Convenient Method for the Homologation of Alcohols via Unstable Aldehydes, J.
First, the Dess-Martin periodinane (DMP) (7.5 mL, 0.3 M solution of DMP in C[H.sub.2][Cl.sub.2]) was added to a C[H.sub.2][Cl.sub.2] (5 mL) solution of 8 (560 mg, 1.6 mmol) under nitrogen.
The efficient production of protected 3-oxocatechin analogue 15 (Scheme 4) with the retention of configuration at C-2 by Dess-Martin periodinane oxidation provided a novel approach towards nucleophilic attack at C-3.
The alcohol compound 3 after workup directly proceeded to oxidation with Dess-Martin periodinane [DMP; 1,1,1-tris(acetyloxy)-1,1-dihydro-1,2-benziodoxol-3-(1H)-one]; this reagent has several advantages over chromium and DMSO-based oxidation reagents that include milder conditions such as lower temperature, neutral pH, shorter reaction times, higher yields, simplified workups, high chemoselectivity, tolerance of sensitive functional groups, and a longer shelf life time.
To a solution of 3 (1 eq) in C[H.sub.2][Cl.sub.2] (400 mL) was added Dess-Martin periodinane (1.1 eq) at RT and the resulting solution was stirred for 2 hours at RT.