Turkish eVisa for Schengen holder single entry

The official website includes the following information:

Egypt: Official passport holders are exempted from visa for their travels up to 90 days. Ordinary passport holders are required to have visa to enter Turkey. Ordinary passport holders may obtain their 30-day single-entry e-Visas via www.evisa.gov.tr, provided that they have a valid Schengen or OECD visa or residence permit and that they travel to Turkey with Turkish Airlines or Egypt Air.

Besides, those ordinary passport holders who are under 20 or over 45 years old may get their 30-day single-entry e-Visas via the website www.evisa.gov.tr.

So Egyptian citizens can get an e-visa (it's best to apply beforehand, no reason to do it at the border) under certain conditions.

But, unfortunately, if you are between 20 and 45 years old, you need a valid Schengen visa (and a ticket from Turkish Airlines or EgyptAir). I don't know how strict Turkish border guards are with all this but your Schengen visa won't be valid anymore on June 6 because it would not allow you to reenter the Schengen area (because you already used the total duration of stay allowed and it was only a single entry visa).

I think you can visit Istanbul either on the way to schengen but please check as different rules exist for citizens of different nationalities. Just apply here: https://www.evisa.gov.tr/en/ (pay them and see if you are issued a visa)

I just arrived from Turkey and entered using e-visa 2 days ago. I am indian, holding schengen residence permit. This is what says in the e-visa.

PLEASE READ CAREFULLY!

My passport covers the period that I will be staying in Turkey.

I can prove that I hold a return ticket, hotel reservation and at least 50 $ per each day of my stay.

I am travelling for the purposes of tourism or business.

I hold a valid supporting document (Schengen visa or a valid visa from any of the OECD member countries; or a valid residence permit of a Schengen or OECD country). e-Visas are not accepted as a supporting document.

also this..

DISCLAIMER In case that the records in your e-visa and passport differ, your e-visa will be deemed invalid. In the event that the information which you provide at your visa application and the information recorded in your passport differentiate, your e-visa will be invalid. If the persons recorded to the accompanying section of your passport are to travel with you, it is essential that they also get e-visa.

E-visa shall not be valid for purposes other than touristic and commercial trips. Visa applications such as work, study, etc. must be made via foreign missions of Turkey.

E-visa system does not monitor the days of your stay/residence in Turkey. Hence, it is your own responsibility to check whether your residence permit has expired or not.

Should your stay upon single entry without residence permit be longer than 30 days, you may well be sentenced to administrative fine and your entry into Turkey might be forbidden for a certain period of time. In exceptional circumstances, it is possible that Turkish authorities may not permit an e-visa-holder to enter into Turkey. For more information, please visit http://www.evisa.gov.tr/info

On entering passport control, please make sure you have these documents, as you might be asked anytime.

1. Return ticket to your destination point.
2. Hotel bookings for the period of stay.
3. Printed copy of e-visa
4. Schengen / OECD visa

I always show them along with my passport. No questions asked from me.