Process of preparing glycolaldehyde

1. A process of preparing glycolaldehyde which comprises reacting formaldehyde with hydrogen and carbon monoxide in the presence of a catalyst composition comprising:

a) a source of rhodium, and

b) a ligand of general formula

R 1 P—R 2   (I)

wherein R 1 is a bivalent radical that together with the phosphorous atom to which it is attached is an optionally substituted 2-phospha-tricyclo[3.3.1.1{3,7}]-decyl group, wherein from 1 to 5 of the carbon atoms have been replaced by a heteroatom, and wherein R 2 is a monovalent radical which is an optionally substituted hydrocarbyl group having from 1 to 40 carbon atoms.

2. A process as claimed in claim 1 , wherein the catalyst composition further comprises c) a source of anions.

3. A process as claimed in claim 1 , wherein bivalent radical R 1 together with the phosphorous atom to which it is attached is a 2-phospha-1,3,5,7-tetralkyl-6,9,10-trioxa-tricyclo[3.3.1.1{3,7}]-decyl group.

4. A process as claimed in claim 1 , wherein monovalent radical R 2 is an alkyl group having from 4 to 34 carbon atoms.

5. A process as claimed in claim 1 , wherein monovalent radical R 2 is of the general formula

—R 3 —C(O)NR 4 R 5   (II)

wherein R 3 is an alkylene group and R 4 and R 5 independently represent an alkyl, cycloalkyl, aryl or alkaryl group, or R 4 and R 5 together represent a bivalent bridging group.

6. A process as claimed in claim 1 , wherein the formaldehyde is aqueous formaldehyde and the reaction is performed in a reaction medium comprising an aqueous phase and an organic phase, wherein the organic phase and aqueous phase are immiscible at 22° C.

7. A process as claimed in claim 6 , wherein the organic phase comprises a water-immiscible amide solvent.