Selectivity to the aldehydes was observed to increase in the presence of surfactant. cetyltrimethylammonium chloride (CTAC). although, phase separation time increased significantly l85 l. Con version of eugenol (98%) with 93% selectivity to aldehydes was reported using [Rh(co)(P2)(TPPMS)12 complex and 1.02 mmol con- centration of CTAC at 80 C and 2.07 MPa syn-gas pressure. The rhodium complex showed higher catalytic activity for the hydro- formy ation reaction than the ruthenium complex. Among the studied ligands, TPPMS ligand was found to be more aldehyde selec- tive than the TPPTS for hydroformylation of eugenol, estragole, safrole and trans-anethole under studied experimental conditions The activity of ruthenium complex was observed in the orde of eugenol> estragole safrole trans-anethole l85 l. The rhodium and ruthenium complexes with both of the studied ligands (TPPMS and TPPTS) showed poor reusability of the catalyst for hydro formylation of eugenol. For aqueous phase hydroformylation of limonene. the addition of small amount of PPh3 (PPh3:TPPTS ratio of 0.05) showed improved conversion of limonene (12% in 21 h) as compared to 115 without PPh3 using dinuclear water soluble TPPTS)21 complex l86]. The authors reported (Rh2(u-StBu)2(co)2 pale yellow color of organic phase which may be due to the leaching of catalyst from the aqueous phase to the organic phase on addition of PPh3 is an important 4-Formyl-3.5.5-trimethylcyclohexan-i-one intermediate for the synthesis of 6-damascone, a floral woody -one perfume. Synthesis of 4-formyl-3.5.5-trimethylcyclohexan-1 of B-isophorone was carried out by the hydroformylation using Rh TPPTS catalyst (Scheme 7 [871. The authors reported 91.7% conversion of B-isophorone in 72 h with 3.1% yield of at 100C100 atm syn 4-formyl-3.5.5-trimethylcyclohexan-1-one gas pressure using mixture of water and toluene as a solvent. The 4-formyl-3.5.5-trimethylcyclohexan-1-one reported lower yield of