US 9,809,528 B2
Production of alpha-hydroxy carboxylic acids and esters from higher sugars using tandem catalyst systems
Marat Orazov, Pasadena, CA (US); and Mark E. Davis, Pasadena, CA (US)
Assigned to California Institute of Technology, Pasadena, CA (US)
Filed by CALIFORNIA INSTITUTE OF TECHNOLOGY, Pasadena, CA (US)
Filed on Jul. 12, 2016, as Appl. No. 15/207,822.
Prior Publication US 2017/0015614 A1, Jan. 19, 2017
Int. Cl. C07C 67/00 (2006.01); C07C 51/00 (2006.01)
CPC C07C 67/00 (2013.01) [C07C 51/00 (2013.01)] 15 Claims
 
1. A method comprising contacting a carbohydrate feedstock with a tandem catalyst system at a temperature in a range of from 60° C. to 200° C., the contacting resulting in the formation of an α-hydroxy carboxylic acid or α-hydroxy carboxylic acid ester, wherein the carbohydrate feedstock comprises a monosaccharide; and
wherein the tandem catalyst system comprises two materially different discrete catalysts, the catalysts being:
(a) a first retro-aldol catalyst, wherein the first retro-aldol catalyst comprises
(i) an optionally substituted oxo(hydroxy)molybdate, an optionally substituted sulfomolybdate, an optionally substituted oxy(hydroxy)tungstate;
(ii) a Ni(II) diamine complex;
(iii) an alkali-exchanged hafno-, stanno-, titano-, or zirconosilicate, an optionally substituted amorphous hafnium-, tin-, titanium-, or zirconium-silicate co-precipitate; or
(iv) a combination thereof; and
(b) a second Lewis acid catalyst, wherein the Lewis acid catalyst comprises a crystalline microporous hafno-, stanno-, titano-, or zirconosilicate containing pores equal to or greater than 10-MR.