Process for preparing chiral compounds

1. A process comprising the step of reacting acetaldehyde with an N-protected aminoaldehyde substrate selected from the group consisting of 3-phthalimidopropionaldehyde, and 3-succinimidopropionaldehyde under aldolase-catalyzed aldol condensation conditions to form the corresponding lactol.

2. The process according to claim 1 , wherein said aldolase is a 2-deoxyribose-5-phosphate aldolase (DERA) aldolase.

3. The process according to claim 2 , wherein said aldolase is DERA 04 comprising a nucleotide sequence of SEQ ID No. 2 or an amino acid sequence of SEQ ID No. 17;

DERA 06 comprising a nucleotide sequence of SEQ ID No. 3 or an amino acid sequence of SEQ ID No. 18;

DERA 101 comprising a nucleotide sequence of SEQ ID No. 8 or an amino acid sequence of SEQ ID No. 23;

DERA 102 comprising a nucleotide sequence of SEQ ID No. 9 or an amino acid sequence of SEQ ID No. 24;

DERA 103 comprising a nucleotide sequence of SEQ ID No. 10 or an amino acid sequence of SEQ ID No. 25;

DERA 104 comprising a nucleotide sequence of SEQ ID No. 11 or an amino acid sequence of SEQ ID No. 26;

DERA 105 comprising a nucleotide sequence of SEQ ID No. 12 or an amino acid sequence of SEQ ID No. 27;

DERA 106 comprising a nucleotide sequence of SEQ ID No. 13 or an amino acid sequence of SEQ ID No. 28;

DERA 107 comprising a nucleotide sequence of SEQ ID No. 14 or an amino acid sequence of SEQ ID No. 29;

DERA 108 comprising a nucleotide sequence of SEQ ID No. 15 or an amino acid sequence of SEQ ID No. 30;

or an aldolase having an amino acid sequence identity of at least about 20% thereof.

4. The process of claim 2 , wherein said aldolase is DERA 04 comprising a nucleotide sequence of SEQ ID No. 2 or an amino acid sequence of SEQ ID No.17; DERA 06 comprising a nucleotide sequence of SEQ ID No. 3 or an amino acid sequence of SEQ ID No. 18; DERA 102 comprising a nucleotide sequence of SEQ ID No. 9 or an amino acid sequence of SEQ ID No. 24.

5. The process according to claim 2 , wherein said aldolase is DERA 04 comprising a nucleotide sequence of SEQ ID No. 2 or an amino acid sequence of SEQ ID No. 17.

6. The process according to claim 2 , wherein said aldolase is DERA 102 comprising a nucleotide sequence of SEQ ID No. 9 or an amino acid sequence of SEQ ID No. 24.

7. The process according to claim 1 , wherein said N-protected aminoaldehyde substrate is 3-phthalimidopropionaldehyde.

8. The process according to claim 1 , wherein said N-protected aminoaldehyde substrate is 3-succinimido-propionaldehyde.

9. The process according to claim 1 , further including oxidizing the lactol so formed to yield the corresponding lactone.

10. The process according to claim 9 , further including reacting the lactone so formed with isopropyl alcohol and acetone to yield the corresponding isopropyl acetonide ester.

11. The process according to claim 9 , further including reacting the lactone so formed with cyclopentanone and isopropyl alcohol to yield the corresponding cyclopentylidene phthalimido isopropyl ester.